diff --git a/libxisf.cpp b/libxisf.cpp
index 660e7f5..e21fc4f 100644
--- a/libxisf.cpp
+++ b/libxisf.cpp
@@ -34,6 +34,7 @@ namespace LibXISF
 std::vector<std::string> splitString(const std::string &str, char delimiter);
 void deserializeVariant(const pugi::xml_node &node, Variant &variant, const ByteArray &data);
 void serializeVariant(pugi::xml_node &node, const Variant &variant);
+Variant variantFromString(Variant::Type type, const String &str);
 
 static std::unordered_map<String, Image::Type> imageTypeToEnum;
 static std::unordered_map<Image::Type, String> imageTypeToString;
@@ -344,13 +345,12 @@ void Image::addFITSKeyword(const FITSKeyword &keyword)
     _fitsKeywords.push_back(keyword);
 }
 
-bool Image::addFITSKeywordAsProperty(const String &name, const Variant &value)
+bool Image::addFITSKeywordAsProperty(const String &name, const String &value)
 {
     if(fitsNameToPropertyIdTypeConvert.count(name))
     {
         auto &c = fitsNameToPropertyIdTypeConvert.at(name);
-        Property prop(c.first, value);
-        //prop.value.convert(c.second);
+        Property prop(c.first, variantFromString(c.second, value));
         updateProperty(prop);
         return true;
     }
diff --git a/libxisf.h b/libxisf.h
index 2587299..e9d77c8 100644
--- a/libxisf.h
+++ b/libxisf.h
@@ -299,7 +299,7 @@ public:
     /** Add image property while doing automatic conversion of FITS name to XISF property
      *  For example OBSERVER => Observer:Name, SITELAT => Observation:Location:Latitude
     */
-    bool addFITSKeywordAsProperty(const String &name, const Variant &value);
+    bool addFITSKeywordAsProperty(const String &name, const String &value);
 
     void* imageData();
     const void* imageData() const;
diff --git a/variant.cpp b/variant.cpp
index 215abbb..91201e7 100644
--- a/variant.cpp
+++ b/variant.cpp
@@ -371,6 +371,27 @@ void serializeVariant(pugi::xml_node &node, const Variant &variant)
         node.append_attribute("value").set_value(ss.str().c_str());
     }
 }
+Variant variantFromString(Variant::Type type, const String &str)
+{
+    Variant variant;
+    switch(type)
+    {
+    case Variant::Type::Int32: variant = fromChars<Int32>(str.c_str(), str.c_str() + str.size()); break;
+    case Variant::Type::Float32: variant = fromChars<Float32>(str.c_str(), str.c_str() + str.size()); break;
+    case Variant::Type::Float64: variant = fromChars<Float64>(str.c_str(), str.c_str() + str.size()); break;
+    case Variant::Type::String: variant = str; break;
+    case Variant::Type::TimePoint:
+    {
+        std::istringstream ss(str);
+        std::tm tm = {};
+        ss >> std::get_time(&tm, "%Y-%m-%dT%H:%M:%SZ");
+        variant = tm;
+        break;
+    }
+    default: break;
+    }
+    return variant;
+}
 
 Variant::Type Variant::type() const
 {